320 PHYSIOLOGICAL CHEMISTRY. 



The origin of the milk-sugar is not known. MUNTZ calls atten- 

 tion to the fact that a quantity of very widely-diffused bodies in 

 the vegetable kingdom vegetable mucus, gums, pectin bodies 

 yield galactose as products of decomposition, and he believes, there- 

 fore, that the milk-sugar may be formed in herbivora by a synthesis 

 from dextrose and galactose. This origin of milk-sugar does not 

 answer for carnivora, as they produce milk-sugar when fed on food 

 consisting entirely of lean meat. The observations of BERT and 

 THIERFELDER that a mother-substance of the milk-sugar, a saccha- 

 rogen, occurs in the glands cannot, as the nature of this mother-sub- 

 stance is still unknown, give further explanation as to the formation 

 of milk-sugar. The question whether the above (page 300) mentioned 

 proteid, which yields a reducible substance when boiled with dilute 

 acids, has anything to do with the formation of milk-sugar cannot 

 be answered until further thorough investigations have been made 

 on this subject. 



The passage of foreign substances into the milk stands in close 

 connection with the chemical processes of the milk-secretion. 



It is a well-known fact that milk acquires a foreign taste from 

 the food of the animal, which is in itself a proof that foreign bodies 

 pass into the milk. This fact becomes of special importance in 

 reference to such injurious substances as may be introduced into 

 the organism of the nursing child by means of the milk. 



Among these substances may be mentioned opium and mor- 

 phine, which after large doses pass into the milk and act on the 

 child. Alcohol may pass into the milk in such large quantities 

 that it produces a stupefying effect on the child. Milk from cattle 

 fed on distiller's grains may also contain alcohol. 



Among the inorganic bodies we find iodine, arsenic, bismuth, 

 antimony, zinc, lead, mercury, and iron in the milk. After inunc- 

 tion-cures PASCHKIS and VAJDA detected mercury in the milk. In 

 icterus neither the bile-acids nor bile-pigments pass into the milk. 



Under diseased conditions no constant change has been found in woman's 

 milk. In isolated cases SCHLOSSBERGBR, JOLY and FILHOL have observed 

 indeed an essential declining composition, but no positive conclusion can be 

 derived therefrom. 



The changes in cow's milk have also been little studied. In tuberculosis of 

 the udder STORCH found tubercule bacilli in the milk, and he also found that 

 the milk became more and more diluted during the disease with a serous liquid 



